How to have a script run from a keypress?
Return a status set from invoke.
AFAICT the issue here is as simple runtime error, not returning a valid status set from an operators invoke method.  No return, returns None.
Pretty obvious from error message printed to system console on testing a keypress.
evt type RIGHT_ARROW
Python: RuntimeError: class KITFOX_OT_grid_rescale, 
function invoke: incompatible return value , , 
Function.result expected a set, not a NoneType

Possible suggestion.
def invoke(self, context, event):
    print(&quot;evt type %s&quot; % (event.type))
    return self.execute(context)

PS in a method where context is passed, common in operators and panels, there is never a need to see bpy.context